Repositório Institucional da Universidade de Aveiro
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The use of communication technologies to support teaching and learning practices in portuguese higher education
No full textThe use of Communication Technologies (CTs) to support teaching and learning in higher education
(HE) has emerged as a research topic worldwide. At the University of Aveiro (Portugal) the TRACER
project began researching in 2011 the use of CTs to support teaching and learning practices in
Portuguese Public Higher Education Institutions (PPHEIs). Data was collected through two online
surveys distributed at two different moments during the project’s life cycle. The first survey, answered
by decision makers at the rectory level of the PPHEIs, focused on the institutional perspective of the
support to the use of CT in their teaching and learning related activities. The second survey, answered
by teachers from the same PPHEIs, focused on the perspective of the use of CT in their teaching
practice.
Results from the institutional perspective globally show that from the total of courses of all existing
cycles in respondent Higher Education Institutions (HEIs), 5.9% are delivered entirely online and 4.2%
in a blended modality, most of them at undergraduate and post-graduate (master) levels. Regarding
the provision of online learning management systems to support teaching and learning, results
showed that the open source platform Moodle is the most commonly adopted, in some HEI coexisting
with other similar platforms. The analysis of the teachers and students usage of these online platforms
shows higher level of use in institutions offering courses online or in blended formats.
From the teachers’ perspective, global results show that interpersonal CTs and institutional learning
management systems are the most used. Regarding pedagogical use, online platforms seem to be
used mostly for dissemination purposes. Communication between teachers and students in class and
extra-class (95,7%) scenarios and the possibility of making available diverse educational resources to
students (93,5%) are recognized as positive issues. The volume of tasks demanded for integrating
CTs in the educational process by teachers is perceived as the most negative aspect (44,3%). Main
reasons for using CTs in the teaching process are student motivation for learning (77,8%) and
innovation in teaching practices (74,6%).
The main results of the project are consolidated in a web-based tool, U-‐TRACER, which provides
support for the handling and deployment of information about the use of CTs through the extensive
use of information visualization features that include specific filters such as: single HE institution
selection or georeferenced filtering. Filtered results can be downloaded and shared in social networks.
This paper provides an overview of the U-‐TRACER project, the methodology adopted for its
development and inherent data collection activities, a brief outline of some results attained through the
surveys applied and, towards the end, a brief presentation of the tool itself and some of the
conclusions drawn from the project as a whole and some perspectives about its future and sustainability
Investigating the molecular systematic relationships amongst selected Plesionika (Decapoda: Pandalidae) from the Northeast Atlantic and Mediterranean Sea
No full textDespite the high number of species and ecological diversity of pandalid shrimps, there has been no previous attempt to resolve evolutionary relationships of several genera using molecular tools. Although mitochondrial DNA cytochrome oxidase I (COI) is widely used in barcoding studies to delimit species boundaries, additional insights into phylogenetic affinities can be obtained, especially when used in combination with data from additional genes. The knowledge of molecular diversity is essential to understand phylogenetic relationships and will help systematic clarifications. Based on partial fragments of the 16S and COI genes, we have focused specifically on addressing the systematic relationships of the economically and ecologically important shrimp genus Plesionika within a framework of five genera from within the Pandalidae. Our results showed that species within Plesionika are substantially divergent when compared with other genera, exhibiting the highest average nucleotide divergence, with 0.1123 and 0.0846 in COI and 16S genes, respectively. In addition, sequence divergence was found to vary greatly within the genus Plesionika (COI/16S): 0.0247/0.0016 between Plesionika antigai and Plesionika heterocarpus and 0.1616/0.098 between Plesionika heterocarpus and Plesionika edwardsii. We did not find amino acid sequence divergence between P. heterocarpus and P. antigai compared with P. heterocarpus and P. edwardsii (8.10%, K2P distance). Three species of Plesionika (P. antigai, P. heterocarpus and Plesionika scopifera) appear well separated from other Plesionika species in both maximum likelihood and Bayesian analyses. The present study confirms the utility of COI over 16S as a genetic marker to resolve relationships between different species of Plesionika from the Northeast Atlantic and Mediterranean Sea, in addition to species delimitation. The findings highlight the need to further review paraphyly within Plesionika in an attempt to recognize a concordance in the evolutionary history of Plesionika with major ecological and geological events
Personal identification in the web using electronic identity cards and a personal identity provider
No full textOn hereditary properties of the class of graphs with convex quadratic stability number
No full textWe show that the class of graphs with quadratic stability number is not hereditary. Then we prove that this class contains a unique maximal hereditary subclass and, finally, we characterize this subclass by two forbidden induced subgraphs
A generalization of chromatic polynomial of a graph subdivision
No full textConsidering the partitions of a set into nonempty subsets, we obtain an expression for the number of all partitions of a given type. The chromatic polynomial of a graph subdivision is generalized, considering two sets of colors, and a general explicit expression is obtained for this generalization. Using
these results, we determine the generalized chromatic polynomial for the particular case of complete graph subdivision
Multiplatform management of a Hard Real-Time Ethernet Switch
No full textThe Hard Real-Time Ethernet Switch (HaRTES) allows using the same network to handle multiple traffic flows, without compromising the performance of real-time applications. Furthermore, it also provides flexible and on-line scheduling techniques with admission control capabilities, thus real-time communications flows can be added, removed and updated online with strict temporal isolation. However, HaRTES lacked a standard management interface to configure its parameters and view its status. This paper describes a multiprotocol (SNMP and NETCONF) management interface design, and implementation. It also presents a preliminary validation of the two management technologies
Fast 802.11 handovers with 802.1X reauthentications
No full textFast handovers of roaming stations (STAs) between access points (APs) require preauthentication or fast reauthentication within new serving APs. The current standards address only over-the-DS (Distribution System) preauthentications for 802.1X authentications. However, over-the-DS preauthentication is not suitable for fast moving STAs, which may loose their connection with the currently serving AP before performing preauthentications in the neighbouring APs. This paper presents several ways to achieve fast 802.11 handovers while keeping the basic security features of 802.1X authentications. To do so, we designed a fast 802.1X reauthentication protocol. This protocol enables an STA to perform many fast 802.1X reauthentications after an initial, possible slow, 802.1X authentication. The reauthentication protocol requires little from the network environment, namely a new, central Reauthentication Service (RS) (possibly integrated with the local 802.1X Authentication Server). To speed up 802.1X reauthentications within handovers, the reauthentication protocol was piggybacked into 802.11 management frames that are ordinarily used during handovers. This way, we are able to perform 802.1X reauthentications while taking the normal, over-the-air 802.11 steps for performing handovers (network probing, authentication, and (re)association). Besides this over-the-air approach, we also show how the 802.1X reauthentication protocol can be implemented using an over-the-DS approach. A prototype implementation using over-the-air 802.1X reauthentication showed that handover delays can be dramatically reduced to 1.5 ms, while an 802.1X fast resume takes more than 150 ms
The dynamics of an online community of practice involving teachers and researchers
No full textIn the literature, communities of practice (CoPs) are recognised as having potential
to promote teachers’ professional development. However, the study of the
dynamics of CoPs with teachers and researchers, and their impact on teachers’
professional development, is still scarce. Contributing to fill this gap, this paper
presents a single case study of the dynamics of a Portuguese online CoP, created
during the research project IPEC. The messages posted by the group’s members
in online fora (the most used communication tool) and descriptive statistics of
the use of the project’s platform are presented and discussed. The analysis shows
different levels of participation among the members over two school years. The
group’s dynamic fits an adaptation of Wenger et al.’s model of CoP development
stages. Finally, this analysis allowed the presentation of suggestions concerning
teachers’ involvement in CoPs and their professional development
Crustal growth and deformational processes in the northern Gondwanan margin: constraints from the Évora Massif (Ossa-Morena zone, southwest Iberia, Portugal)
No full textThe aim of this article is to present a compilation of available information on
the Évora Massif based on structural mapping, whole-rock geochemistry, recognition of metamorphic mineral assemblages, and geothermobarometry. In our view, transcurrent
movements responsible for strong orogen-parallel stretching were dominant
and had a major role in the geodynamic evolution of this part of Ossa-Morena zone
(southwest Iberian Massif). Cadomian and Variscan orogenic events separated by a
period of intense rifting were the cause for the composite distribution of zones with
contrasting metamorphic paths, the structural complexity, the variety of lithological
associations, and the sequence of deformation events and magmatism. The proposed geodynamic reconstruction for this segment of the northern Gondwana continental margin includes three main stages in chronological order: (1) Neoproterozoic accretion and continental magmatic arc developing, dismantling, and reworking, followed by late-“orogenic” magmatism; (2) Lower Paleozoic crustal thinning, block tilting, and mantle upwelling, induced by generalized rifting, leading to the formation of marine basins with carbonate platform sediments and thick accumulations of volcaniclastic and terrigenous sediments, contemporaneous with normal and enriched mid-oceanic ridge basalt–type magmatism; and (3) Upper Paleozoic transpressional orogenesis resulting from obliquity of convergence and the geometry of the involved blocks. The third stage includes the tectonic inversion of Lower Paleozoic basins, crustal thickening, the exhumation of high- to medium-pressure rocks and partial
exhumation of high-grade metamorphic lithologies (controlled by local transtension
and major detachments), the formation of synorogenic basins filled with volcanicsedimentary sequences, and finally, the emplacement of late Variscan granodiorites and granites
Edición y comercio del libro en Portugal
No full textEn la génesis de este proyecto preponderan aspectos resultantes del contexto progresivamente más desfavorable en el que a lo largo de la última década se viene ejerciendo el comercio tradicional en la librería, muy especialmente en las librerías independientes de grupos económicos o editoriales y libreros.
En este ámbito, conviene constatar que debido a la gran diseminación y diversidad de protagonistas, bien como de locales y estrategias de venta de libros, aumentan las prácticas de competencia agresiva por parte de algunos de los principales actores, susceptibles de no estar conformes con la Lei do
Preço Fixo do Livro (vigente en Portugal desde 1996) y que a finales de 2013 se tradujeron en una queja conjunta que 26 libreros independientes presentaron
a la Inspeção Geral das Actividades Culturais (IGAC), el organismo cultural responsable en Portugal de la fiscalización de la aplicación de la Ley.
La estrategia de la búsqueda que desarrollamos tuvo en cuenta el marco de la evolución histórica del libro en los ámbitos cultural y socioeconómico,
del caso portugués en el contexto internacional (particularmente en la Unión Europea) y del comercio del libro en el mercado librero.
Fueron utilizadas fuentes secundarias, fundamentalmente documentales y estadísticas, a partir de las cuales se construyeron tablas cronológicas y series estadísticas. Se utilizaron igualmente fuentes primarias, tanto a través de
entrevistas de encuadramiento exploratorio junto a editores y libreros, como también entrevistas dirigidas al universo particular de las librerías independientes.
Además de la presentación de resultados, tanto desde el punto de vista de la edición como de la comercialización, y de los posicionamientos de los
libreros independientes entrevistados sobre las diversas dimensiones del sector del libro, se identifican las principales tendencias resultantes de los contextos
internacional y nacional, y se hace una síntesis diagnóstica del comercio librero en Portugal basada en un análisis en el que fueron consideradas las dimensiones sociocultural, económica, tecnológica y político cultural